Biomedical Engineering Reference
In-Depth Information
species. Only recently, however, have the conscious efforts of human activities complemented
these sources of nanomaterials. This development is due to the ability of being able to con-
trol and manufacture nanoparticles of different sizes and shapes in research laboratories
and industrial plants. As a result, engineered nanomaterials have been created. The capa-
bility not only to produce, but also to manage, create, and manipulate various character-
istics of nanomaterials, has initiated rapid interest and development of novel species.
Nanotechnology encompasses manipulation, application, and manufacturing of various
nanomaterials based on their atomic-scale properties. The fast progress of nanotechnology
has been possible due to the development of nanotools - devices that allow operating on
and control of material at the nano, atomic, and molecular scales. The list of such nanotools
is still growing, and includes atomic-force microscopes (AFM), scanning tunneling micro-
scopes (STM), atomic-layer-deposition devices, and various nanolithography tools: impor-
tant factors in the development of novel nanomaterials are fabrication techniques that
include instruments used for analysis and metrology.
Nanotechnology
Nanomaterials can be assembled into entire systems comprising nanostructured compo-
nents that perform various tasks other than material manipulation: such systems are called
nanodevices. They are already being manufactured and have become vital components of
various advanced technologies. Examples include micro-electro-mechanical systems
(MEMS) used as accelerometers in automotive airbags and in iPhones, medical scalpels, and
fluorescent biodetectors, which are based on quantum dots [20]. Nanosensors, drug-delivery
systems, and nanoelectronic memory tools are currently under development. It can be
expected that in the near future industry and commerce will benefit from the invention and
fabrication of more nanodevices, which are essential to facilitate streamlined efficiency,
increase product reliability, and reduce production costs.
In the field of public health, nanotechnology has also secured a vital role. Nanomedicine
can be defined as the application of nanotechnology for diagnosis, monitoring, control, and
treatment of biological systems [21]. Various nanomaterials are used for such applications,
including nanoparticles that are biological mimetics, nanofibers and polymeric nanocon-
structs for use as biomaterials, sensors, and laboratory diagnostics. In the arena of environ-
mental health, nanotechnology is essential in the development and application of tools to
assess human and biota exposure to hazards, and to assess interactions between genes and
the environment. Innovative approaches are necessary to characterize and evaluate environ-
mental risk from nanomaterials, and to provide a link between environmental exposure and
diseases in both humans and animals [22].
Classification of Nanomaterials
Nanomaterials can be divided into different groups based on a broad range of criteria.
There are many distinct types of nanomaterials and various systems of classification have
been proposed. Nanoparticles can be categorized into three groups according to dimension:
(i) one-dimensional nanowires, nanotubes, very thin fibers, capillaries and pores;
(ii) two-dimensional carbon nanotubes formed by rolling graphene layers, cylinders, and
fullerenes; (iii) three-dimensional clusters, crystals, and larger structures [23, 24]. Scientists,
however, have also recently proposed classifying nanoparticles into four groups that include
a zero-dimension [25, 26]. Another classification scheme that introduces nine categories of
